| | Marysville, CA | Alturas, CA | United States |
| Population | 12,451 | 2,693 | 329,725,481 |
| Female Population | 49.4% | 52.8% | 50.5% |
| Male Population | 50.6% | 47.2% | 49.5% |
| Median Age | 35.4 | 44.8 | 38.4 |
| space3 | | | |
| Population - 2010 | 12,072 | 2,837 | 309,327,143 |
| Population - 2000 | 12,268 | 2,892 | 285,036,114 |
| Population - 1990 | 12,324 | 3,231 | 251,960,433 |
| Pop. 2000 to Now | 2.7% | -12.1% | 15.6% |
| Pop. 1990 to Now | 2.2% | -21.3% | 30.8% |
| space4 | | | |
| Population Density | 3,594.4 | 953.6 | 93.4 |
| Land Area | 3.5 | 2.8 | 3,531,905.4 |
| Water Area | 0.1 | 0.0 | 264,836.8 |
| space | | | |
| Est. Total Population By Age | | | |
| | Marysville, CA | Alturas, CA | United States |
| Age 0 to 4 | 6.1% | 8.8% | 5.9% |
| Age 5 to 9 | 6.6% | 6.5% | 6.1% |
| Age 10 to 14 | 7.8% | 3.4% | 6.6% |
| Age 15 to 17 | 5.7% | 2.1% | 3.9% |
| Age 18 to 20 | 3.4% | 1.4% | 4.0% |
| Age 21 to 24 | 4.9% | 3.7% | 5.2% |
| Age 25 to 34 | 14.8% | 16.9% | 13.8% |
| Age 35 to 44 | 13.5% | 7.5% | 12.9% |
| Age 45 to 54 | 11.0% | 8.1% | 12.6% |
| Age 55 to 59 | 5.5% | 8.9% | 6.7% |
| Age 60 to 64 | 7.3% | 6.1% | 6.3% |
| Age 65 to 74 | 7.9% | 16.8% | 9.6% |
| Age 75 to 84 | 4.4% | 8.1% | 4.5% |
| Age 85 and over | 1.1% | 1.6% | 1.9% |
| space1 | | | |
| Race | | | |
| | Marysville, CA | Alturas, CA | United States |
| White | 60.9% | 68.9% | 59.4% |
| Black | 1.2% | 4.2% | 12.2% |
| Asian | 4.3% | 0.0% | 5.6% |
| Native American | 0.3% | 1.7% | 0.6% |
| Hawaiian, Pacific Islander | 0.0% | 0.0% | 0.2% |
| Other | 0.4% | 0.0% | 0.4% |
| Two or More Races | 5.5% | 3.3% | 3.2% |
| Hispanic | 27.4% | 21.9% | 18.4% |
| space2 | | | |
| Marriage & Family | | | |
| | Marysville, CA | Alturas, CA | United States |
| Married Population | 39.5% | 51.6% | 49.8% |
| Currently Married | 36.6% | 50.4% | 48.0% |
| Married but Separated | 2.8% | 1.2% | 1.8% |
| Single Population | 60.5% | 48.4% | 50.2% |
| Never Married | 39.6% | 20.3% | 33.8% |
| Divorced | 14.6% | 20.5% | 10.8% |
| Widowed | 6.4% | 7.6% | 5.6% |
| space5 | | | |
| Household Size | 2.49 | 2.30 | 2.60 |
| Households | 4,773 | 1,159 | 124,010,992 |
| Family Households | 2,868 | 678 | 80,755,759 |
| Married couple, w/children | 25.9% | 21.2% | 30.5% |
| Married couple, no children | 26.5% | 52.4% | 42.9% |
| Non Family Households | 1,905 | 481 | 43,255,233 |
| Single householder, w/children | 30.9% | 19.8% | 15.8% |
| Single householder, no children | 16.7% | 6.6% | 10.8% |